Staggered reinforcement for concrete structures



1969 5. OROSCHAKOFF 6 STAGGERED REINFORCEMENT FOR CONCRETE STRUCTURES Filed Aug. 11. 1967 7 Sheets-Sheet 1 FIG./

INVENTOR.

GEORGI OROSOHAKOI'F 69 s. OROSCHAKOFF 3,475,875

STAGGERED REINFORCEMENT FOR CONCRETE STRUCTURES Filed Aug. 11, 1967 7 Sheets-$heet 2 FIG. 4

INVENTOR.

GEORGI OROSCHAKOFF may, Tm;

Attorney N 1969 s. OROSCHAKOFF 3,475,375

4 STAGGERED REINFORCEMENT FOR CONCRETE STRUCTURES Filed Aug. 11, 1967 7 SheetsSheet 5 nae INVENTOR.

GEORGI OROSCHAKOFF :Karl

Attorne Nov. 4, 1969 e. (JROSCHAKOFF 3,475,876

STAGGERED REINFORCEMENT FOR CONCRETE STRUCTURES Filed Aug. 11, 1967 7 Sheets-Sheet 5 FIG. /6

FIG. I7

FIG/8 /2 a; A A A A h A U U J1 /0 FIG. /9

FIG. 20

l wafi- 1B INVENTOR. GEORGI OROSCHAKOF? Attorney Nov. 4, 1969 QRQSCHAKOFF 3,475,876

STAGGERBD REINFORCEMENT FOR CONCRETE STRUCTURES Filed Aug. 11, 1967 '7 Sheets-Sheet 6 FIG. 2/

4 I %%%Q I5 I 1 INVENTOR. GEORGI OROSCHAKOFE 5 :K r jam Attomev Nov. 4, 1969 G. OROSCHAKOFF 3,475,876

STAGGERED REINFORCEMENT FOR CONCRETE STRUCTURES '7 Sheets-Sheet 7 Filed Aug. 11. 1967 FIG 3/ FIG. 3?

INVENTOR. GEORGI OROSCEQKOFF US. Cl. 52581 12 Claims ABSTRACT OF THE DISCLOSURE Two separate mesh sections extend from opposite ends of the reinforcement and overlap over part of the distance between said ends. The sections being in modular relationship with lengths equal to integral numbers of a unit length.

This invention relates to a staggered reinforcement for concrete structures.

In the construction of staggered two-dimensional reinforcements of spot-welded reinforcing mesh sections, a long mesh section is used, which extends throughout the span from one support to the other, and a shorter mesh section is disposed over the long mesh section.

The mesh sections which are used at the present time are made with uniform dimensions of 600 cm. x 240 cm. and with different rod cross-sections. Each of the known types is thus made from rods which differ in thickness. When such mesh sections are used as reinforcements for slablike elements, they are dimensioned with consideration of the maximum moment so that the consumption of steel is much larger than actually needed because the crosssectional area of steel required for the maximum moment is present throughout the length of the section but is utilized only in the region of the maximum moment. This unnecessary steel may amount to as much as 40% of the entire consumption.

The steel requirement is reduced by the abovementioned, staggered arrangement of a longer mesh section and a shorter one, super-imposed thereon. As the required length of the shorter mesh section varies, there will always be waste portions so that the steel consumption is still uneconomically high.

The staggered reinforcement according to the invention consists particularly of a two-dimensional reinforcement, such as a steel grid mesh, and avoids the abovementioned disadvantage of known reinforcements in that it consists of two separate mesh sections, each shorter than the span of the slab, adapted to be superimposed from opposite ends of the span to form a staggered two-dimensional reinforcement which meets the static requirements.

As a final result of the invention, the two-dimensional reinforcement designed to meet the requirements imposed by the span, load, static stress diagram and thickness of slab is divided into two standardized two-dimensional reinforcements, which can be manufactured industrially and form parts of a modular system having different mesh section lengths. The term modular is here used in its general sense to refer to sections whose lengths are each an integral number of unit lengths. These sections are superimposed, beginning at the supports, to form the re quired two-dimensional reinforcement. It has been found that the required rod cross-section of a twodimensional reinforcement depends in an amount of 80% on the span and in an amount of only 20% on the usual loads and slab thicknesses. This determines the length increments between the modular sections for the two-dimensional reinforcements, depending on the cross-section of the rod which is employed.

United States Patent Patented Nov. 4, 1969 "Ice The design according to the invention enables a full adaptation to the steel cross-section which is statically required while the steel consumption is minimized; besides, my present improvement affords a close adaptation to the slab sizes used in practice without need for cutting the reinforcement, as was previously required and involved an unnecessary consumption of steel and expenditure of work, also a complete standardization of the various twodimensional reinforcement sections for a wide production program, and a reduction of the number of mesh section types as well as a reduction of the number of rods compared with conventional methods of manufacture.

To enable a design of load-carrying reinforced members, such as columns, beams and the like in accordance with the invention, the same provides also a staggered reinforcement for the load-carrying elements of reinforcedconcrete structures, this reinforcement consisting of at least two separate sections, which are two-dimensional or angle-shaped and can be assembled by being arranged one beside the other from opposite ends of the span.

It is thus possible to assemble the two-dimensional reinforcement for the slabs as well as the reinforcement for the beams or the like from modular sections so that all beam widths and spans can be provided for with any desired cross-sections. According to the invention, the beam reinforcement consisting in the usual manner of a basket structure is composed of two-dimensional and/or angle-shaped modular sections, which are always used in pairs. The sections may be alike or different. Each of the sections of the reinforcements has one end disposed at the end of the span and another end terminating in the beam. The rod cross-section of the resulting staggered reinforcement may be selected in keeping with the variation of the moment. This selection is effected in length by a displacement of the two sections of the reinforcement. Where at least four sections are provided, they may be staggered also in height. Pairs of these sections may be superimposed and may be arranged on such levels as to meet the requirements imposed by the load.

Further features and advantages of the invention will become apparent from the subsequent description of embodiments of the invention shown by way of example on the accompanying drawing in which:

FIGS. 1 and 4 are top plan views showing one section of two different embodiments of a two-dimensional reinforcement;

FIGS. 2 and 5 show the two-dimensional reinforcement consisting of two such sections, which are superimposed in staggered relation;

FIG. 3 is a section along line Il1-III of FIG. 2;

FIG. 6 is a top plan view of sections having different lengths according to a modular system;

FIG. 7 is a cross-section similar to FIG. 3, but of sections having different total cross-sectional areas;

FIGS. 8 and 9 are, respectively, a side elevation and an end elevation showing a section of a reinforcement for a beam;

FIG. 10 is a side elevation showing a reinforcement composed of two such sections, which are superimposed in staggered relationship;

FIGS. 11 and 12 show a modification of FIGS. 8 and FIG. 13 is an end elevation showing a reinforcement composed of two such sections according to FIG. 11;

FIG. 14 is a view similar to FIG. 8 and shows a further modification;

FIG. 15 is a side elevation showing a reinforcement composed of two such sections according to FIG. 14, superimposed in staggered relationship;

FIG. 16 is a side elevation showing a supplementing section for the reinforcement of FIG. 8;

FIG. 17 is a side elevation showing one half of the reinforcement which comprises the sections shown in FIGS. 8 and 16, but staggered in height;

FIG. 18 is a side elevation of a reinforcement composed of two reinforcements according to FIG. 17, but in superimposed staggered position;

FIG. 19 is a side elevation showing a further modification of a section as shown in FIG. 8;

FIG. 20 is a side view showing one half of a reinforcement comprising two such sections staggered in hei ht;

F IGS. 21 and 22 show further modifications of FIGS. 19 and 20, wherein each of the transverse means is composed of a double rod;

FIGS. 23, 24 and 25 are, respectively, two end views and a perspective view showing an angle-shaped reinforcing section;

FIGS. 26 and 27 show two modifications of the section of FIG. 25;

FIG. 28 is a transverse-sectional view showing a beam having a reinforcement which is composed of the sectiohs according to the invention;

FIG. 29 is a perspective view of the retaining member used therein;

FIGS. 30 and 31 are views similar to FIGS. 28 and 29 and show modifications; and

FIGS. 32, 33 and 34 are transverse sectional views showing rib structures of a colfered slab and of an Ast- Moulin floor provided with reinforcing sections according to the invention.

As is apparent from FIG. 1, each of the identical parts 1, 2 of the two-dimensional reinforcements consists of a grid comprising longitudinally extending, load-carrying lower rods 3, 4, including longer rods 3 and shorter rods 4, and load-distributing, transversely extending upper rods of identical length, which are welded to the rods 3, 4 at the crossing points so that the rods 5 lie on one side of the grid section and are coplanar. The arrangement is such that at one longitudinal edge of the mesh section (the lower edge in FIG. 1), the spacing between the rods 3, 4 is only one-half the distance to an adjacent inner bar 3.

For use as a staggered reinforcement, two identical mesh sections are superimposed as is shown in FIG. 2 and in such a manner that one section 1 as shown in FIG. 1 is held in position and the next section 2, which has initially the same attitude, is rotated through 180 in each of two directions, first in a horizontal plane and then about its longitudinal axis. This results in the longitudinally overlapping transversely staggered two-dimensional reinforcement shown in FIG. 2. The edge where the ends of the rods 3, 4 of the first mesh section 1 are aligned extends along the left-hand support 6 in FIG. 2 and the corresponding edge of the second mesh section 2 extends along the right-hand support 7. It is apparent from FIG. 2 that, e.g., the rods 4 of the mesh sections 1, 2 extend across one half of the span (0.5L) and that the remaining parts of the span toward the supports have steel cross-sections decreasing in area in two steps, namely 2x0.1L and 2X0.15L, so that a stress distribution corresponding to the static requirements can be achieved. Another advantage of the design according to the invention resides in that the load-carrying longitudinal rods 3, 4 of both mesh sections 1, 2 lie, as shown in FIG. 3, in the same plane in the assembled condition shown in FIG. 2, whereas the load-distributing rods 5 of the mesh section 1 are at the bottom and those of the mesh section are at the top.

According to the invention, the sections 1, 2 form mesh sections of a modular system having different lengths, as shown in FIG. 6, so that a given load condition can be met by the selection of sections 1 of suitable length and of the overlap thereof, whereby a cutting of the mesh sections is not required. If a unit length is taken as the spacing between two bars 5, the topmost section in FIG. 6 represents the product of the integer 7 with the unit length, the next lower section corresponds to the product of the integer 8 with the unit length, etc. The division of the reinforcement into two identical sections 1, 2 enables an adjustment to any desired span length within a certain range by a relative displacement of these two sections as in a vernier. This range corresponds to one size increment of the modular system. When the maximum or minimum span of this range is reached, the next size of the modular system must be used,"if required.

A modification of this design is shown in FIGS. 4 and 5. In this modification, a single transverse rod 8 is disposed at one edge of the mesh section and two transverse rods 9, 10 are disposed at the opposite edge. The rods 8, 9 and 10 extend at right angles to the longitudinal rods 3, 4. A number of additional loaddistributing transverse members 11 extend at an angle of to the longitudinal rods 3, 4. FIG. 5 shows the twodimensional reinforcement which is obtained by superimposing two such mesh sections in staggered position. Compared to the design shown in FIGS. 1 and 2, this modification has the advantage that in the intermediate area, where the mesh sections 1, 2 overlap, the inclined load-distributing transverse members 11 cause a constant network of rods crossing in three or four directions to be obtained also by the above-mentioned relative vernier like displacement.

Modifications of the two two-dimensional reinforcements shown by way of example are possible. As seen in FIG. 7, it is possible to superimpose two sections 1, 2, the rods 3, 4 thereof having different cross-sectional areas. Mesh sections 1, 2 of different length may be used according to the invention as a staggered reinforcement.

The section 10 shown in FIGS. 8 and 9 for the reinforcement of a beam of reinforced concrete consists of two parallel longitudinal rods 1, the lower one of which constitutes .a main reinforcing member, and of transverse load-distributing transverse members 2 which are connected to the rod 1 and are formed by a zig-zag rod, dis posed between the rods 1 so as to form turning points which are more closely spaced in the left-hand half of the section than in the right-hand half. The rods 1, 2 may be joined, as shown, by welding or by other means, such as straps or the like.

FIG. 10 shows the reinforcement which is obtained when two such sections 10, 10 according to FIGS. 8 and 9, extending from opposite ends of the span, are superimposed. A certain span range can be covered by one size of the modular system by a relative displacement of two identical sections, as shown in FIG. 5, in the longitudinal direction indicated by an arrow A.

The design shown in FIGS. 11, 12 and 13 differs from the designs of FIGS. 8, 9 and 10 in that two lower main reinforcing members rather than a single one are provided in the section 10 and the upper one of said reinforcing members is shorter than the lower one.

In the embodiment shown in FIGS. 14 and 15, the upper one of the two lower main reinforcing members extends upwardly at one end to the second upper longitudinal rod in order to take up shear or thrust forces.

FIG. 16 shows a'supplementary section 12, which can be used together with the section 10 of FIG. 8 in beams having a relatively large height. This supplementary section consists also of two parallel longitudinal rods 30 and a zigzag transverse rod 40. The arrangement of this section 12 in conjunction with an element 10 as per FIG. 8 is shown in FIG. 17. Beams having different heights may be obtained by a relative vertical displacement in the direction indicated by the arrow B. It will be understood that FIG. 17 shows only one half of such a reinforcement for a beam. The second half consists also of a section 10 and a section 12 and extends from the other end of the span in an arrangement which is similar to that shown in FIGS. 10, 13 and 15; this arrangement is shown in FIG. 18.

In the section shown in FIGS. 19 and 21 respectively, single rods 50 or double rods 51, e.g. so-called Bistahl rods, are shown. The latter rods 51 are interconnected at their ends not only by the longitudinal rods 1 but additionally by transverse members 60. FIGS. and 22 respectively show one reinforcement half consisting of two such sections and be adaptable to beams of different heights by a displacement in the direction of the arrow B.

As reinforcements in beams, angle-shaped sections may be used instead of or in addition to the two-dimensional sections described hereinbefore. Such an angle-shaped section 31 is shown in an end view of FIGS. 23 and 24 respectively and consists of straight longitudinal rods 21 and load-distributing transverse members 22. This is also apparent from FIG. 25 in a perspective view. FIG. 24 shows a modification of a section of FIG. 23 having different cross-sectional areas of the rods 21. The angleshaped single rods 22 may be replaced by angle-shaped double rods 25 having cross-members 26, as is shown in FIG. 26. The load-distributing transverse members may also consist of an angled zigzag rod 27, as is shown in FIG. 27. Within the modular system mentioned before (FIG. 6), these angle-shaped elements are made in constant lengths but with graded arm lengths and steel cross-sections and can be used to take up the peak moments at the columns.

FIG. 28 shows a reinforcement consisting of sections according to the invention for use in a beam which is rectangular in cross-section. The reinforcement consists of four sections 10, 10' as per FIG. 8 and the angle-shaped sections 31 of FIG. 23. During the insertion into the formwork, the two-dimensional sections are suitably held in position by specially shaped holding members 13, which are indicated in dotted lines in FIG. 28 and in perspective in FIG. 29. Additional reinforcing rods 14 may be arranged in the edge zones of the beam (FIG. 28). It will be understood that the design of the retaining member may be changed as desired. They may alternatively consist of two or more parts or of diagonal struts.

FIG. 30 shows a different beam, which is similar to that of FIG. 28, with the dilference that the beam is a T-section because the angle-shaped sections 31 have arms extending toward each other. The retaining member 13 is indicated in dotted lines and may be shaped, e.g., as shown in FIG. 31.

FIGS. 32-34 show tWo rib beams for use in coifered ceilings and a beam for an Ast-Moulin floor. These beams are provided with reinforcement sections according to the invention. In FIG. 32, two-dimensional sections 10 corresponding to FIG. 8 are arranged so that their load-distributing transverse members 2 are disposed in one plane and their longitudinal rods 1 are disposed at the same height. The longitudinal rods 1' of the associated two-dimensional sections 10' are indicated in dotted lines. FIGS. 30, 33 and 34 show spacers 15 for the two-dimensional sections 10, 10'. In FIGS. 28 and 32-34, the reinforcing mesh sections shown in FIGS. 1-4 are designated 16. The concrete in which the reinforcements are embedded is designated 70 in FIGS. 28, 30, 32, 33 and 34.

Numerous modificaitons of the described embodiments are possible within the scope of the invention.

What is claimed is:

1. A reinforcement assembly for concrete slabs, comprising at least a pair of grid sections extending inwardly from respective opposite ends of the slab and overlapping superposed at an intermediate zone thereof; said sections each including a plurality of transversely spaced mutually parallel longitudinally extending reinforcement bars lying in a common plane and forming an array, alternate longitudinal bars of said array being shorter than intervening longitudinal bars thereof, all of the bars of the array terminating at the corresponding end of the slab, and a plurality of coplanar mutually parallel spaced-apart transverse bars spanning the array of longitudinal bars while being welded thereto at the crossing points and being disposed on one side of the array; the longitudinal bars of the superposed sections at said zone being transversely staggered and lying in a plane common to both said arrays, whereby the arrays of longitudinal bars are disposed between the planes of the transverse bars,

r said sections being in modular relationship with lengths equal to integral numbers of a unit length.

2. The assembly defined in claim 1 wherein said sections are of identical dimensions and configurations.

3. The assembly defined in claim 1 wherein said sections have different dimensions.

4. The assembly defined in claim 1 wherein said sections are of the same length.

5. The assembly defined in claim 1 wherein said sections are of different length.

6. The assembly defined in claim 1 wherein said sections have identical steel cross-sectional areas.

7. The assembly defined in claim 1 wherein said sections have different steel cross-sectional areas.

8. The assembly defined in claim 1 wherein said sections are generally horizontal, said opposite ends are horizontally spaced and said sections are stacked one above the other in said zone.

9. The assembly defined in claim 8 wherein at least some of said transverse bars cross said longitudinal bars at oblique angles.

10. The assembly defined in claim 1 wherein at least one of said sections is of angular cross-section.

11. The assembly defined in claim 1 wherein said transverse bars are constituted at least in part by a zigzag rod.

12. The assembly defined in claim 1 wherein the undulations of the zigzag rod are more closely spaced at one end of each section than at the opposite end thereof.

References Cited UNITED STATES PATENTS 1,173,901 2/1916 Turner 52-660 3,300,938 1/ 1967 Van Schyndel et a1. 52-664 X 3,302,360 2/1967 Sven-Erik Bjerking 52-687 X 3,364,640 1/ 1968 Guddal 52-694 X FOREIGN PATENTS 179,885 10/ 1954 Austria.

191,137 8/1957 Austria.

630,011 7/ 1963 Belgium. 1,118,750 3/1956 France.

728,866 4/ 1955 Great Britain.

999,417 7/ 1965 Great Britain.

169,982 9/ 1934 Switzerland.

384,834 2/1965 Switzerland.

OTHER REFERENCES German printed application 1,134,816, August 1962.

ALFRED C. PERHAM, Primary Examiner US. 01. X.R. 

